Method and apparatus for treating granulized coffee

ABSTRACT

The method and apparatus for treating granulized coffee delivered from a granulizing mill. The coffee from the mill is conveyed into the lower portion of an upright mixing chamber having a rotating agitator with mixing blades inclined at an angle to move the material upwardly while mixing. The pressure head of the material in the chamber is controlled to achieve improved mixing conditions. The blades in a flight at the chamber discharge end have a reverse pitch for restricting flow through the chamber, and the discharged material is delivered to a scalper for subsequent treatment.

United States Patent Inventors Otto C. Krolopp Villa Park, Ill.;

Leon J. Nowak, Liverpool, N.Y. 822,229

May 6, 1969 Oct. 5, 1971 Blew-Knox Company Pittsburgh, Pa.

Appl. No. Filed Patented Assignee METHOD AND APPARATUS FOR TREATINGGRANULIZED COFFEE 19 Claims, 3 Drawing Figs.

U.S. Cl 241/2, 241/13, 241/29, 241/152 R, 241/188 R, 24l/284, 259/8,259/44 lnt. Cl B02c 3/04, B0,2c 4/02, B02c 13/24 Field of Search241/6-13,

[56] References Cited UNITED STATES PATENTS 2,202,936 6/1940 Williams241/284 X 3,329,350 7/1967 Wisgerhof 241/188 X Primary ExaminerDonald G.Kelly AttorneyParker, Carter & Markey ABSTRACT: The method and apparatusfor treating granulized coffee delivered from a granulizing mill. Thecoffee from the mill is conveyed into the lower portion of an uprightmixing chamber having a rotating agitator with mixing blades inclined atan angle to move the material upwardly while mix ing. The pressure headof the material in the chamber is controlled to achieve improved mixingconditions. The blades in a flight at the chamber discharge end have areverse pitch for restricting flow through the chamber, and thedischarged material is delivered to a scalper for subsequent treatment.

METHOD AND APPARATUS FOR TREATING GRANULIZED COFFEE SUMMARY OF THEINVENTION This invention relates to an improved method and apparatus fortreating granulized coffee. More particularly the invention relates to amethod and apparatus for mixing and agitating coffee from a granulizerto achieve increased output capacity and machine efficiency while at thesame time obtaining an improved product.

Coffee beans are conventionally prepared for consumer use by roasting,granulizing in a mill, mixing the granulized particles to the densityand appearance desired, treatment in a scalper mechanism to separateoversized material, and delivery to the packaging operation. The patentsto l-lazle, .lr., U.S. Pat. No. 2,118,010, 2,204,591 and 2,323,771disclose apparatus in which the granulizing mill delivers the coffee toa horizontal tub-type mixer. The granulized coffee is agitated in themixer to hide or camouflage the light-colored chafi by absorbing smallamounts of oil from the coffee. Otherwise the light-colored chaff wouldgive the coffee product an undesirable appearance.

The industry has been seeking to increase the capacity and efficiency ofthe granulizer-mixer equipment while maintaining the desirable standardsof appearance and quality for the coffee product. Merely increasing thesize and speed of the equipment is not entirely satisfactory as it isnecessary to carefully control the amount of oil release from thecoffee, the amount of comminution of chaff, and the compactability orbulk density of the coffee produce. It is also desirable that the amountof temperature rise during the granulizing-mixing steps be kept at a lowlevel to control oil release and reduce the time required for coolingbefore the coffee can be packaged.

Accordingly, it is an object of this invention to provide an improvedmethod and apparatus for treating cofiee in which granulized coffee isdelivered to a mixing chamber where pressure a pressure head ismaintained on the material as it is agitated and moved upwardly throughthe chamber for discharge.

Another object is to provide an improved method and apparatus fortreating coffee in which granulized coffee is delivered into the lowerend of an upstanding mixer chamber having rotating mixing blades adaptedto move the coffee upwardly to the discharge end, and with means tomaintain a predetermined head on the material in the chamber to achieveoptimum comminution and oil absorption in the chaff, reduce thetemperature rise during mixing, reduce the quantity of fines in thecoffee, and increase the bulk density for an improved coffee product.Another object is to provide an improved mixer for use in a coffeetreating apparatus in which granulized coffee is moved upwardly to amixing chamber by rotating blades which agitate the coffee particles,break down the chaff and color it by absorption of oil released from thecoffee particles under pressure in the mixer, and in which rotatingblades near the mixer discharge function to supplement the pressure headon the particles.

Another object is to provide a mixer apparatus for granulized coffee inwhich an upstanding mixing chamber and rotating agitator develop animproved mixing action and transformation of the coffee chaff bydeveloping a gravity head on the coffee during mixing, and bycontrolling the rate of discharge from the chamber as a function of thecoffee input rate and additional head desired.

Another object is to provide the method and apparatus for treatingcoffee by granulizing coffee beans, conveying the granulized coffee byauger means to the lower portion of a substantially vertical mixingchamber, moving the coffee upwardly through the chamber at a controlledrate to maintain a predetermined gravity head, mixing the coffee in thechamber to comminute chaff and absorb oil from the coffee into thechaff, and control the rate of discharge from the upper portion of thechamber as a function of the total head on the coffee desired foroptimum mixing.

Another object is to provide the method and apparatus for mixinggranulized coffee in an upward flow path productive of increasedcapacity with relatively low power requirements.

These and other objects and advantages of the invention will becomeapparent to those skilled in the art when the following specification isread in conjunction with the accompanying drawings.

DESCRlPTlON OF THE DRAWINGS FIG. 1 is a side elevation view, partiallysectioned with certain elements removed for clarity, illustrating anapparatus for treating coffee according to the invention.

FIG. 2 is a top plan view of the apparatus of FIG. 1 with elementsremoved for clarity.

FIG. 3 is a side elevation view of a mixer rotor for the coffee-treatingapparatus of the invention.

DETAILED DESCRIPTION Referring to the drawings and particularly FIG. 1 acoffeetreating apparatus embodying features of the invention isillustrated generally at 10 and comprises a granulizer 12, screwconveyor 14, and mixer assembly 16 which discharges at outlet 18.

Granulizer 12 functions to comminute or reduce roasted coffee beanswhich are delivered from supply hopper 20 and fed at a controlled rateonto a plurality of granulizing rolls 22, 24. The granulizer may be ofthe type disclosed in copending application Ser. No. 579,634, filedSept. 15, 1966 by Otto C. Krolopp, now U.S. Pat. No. 3,491,952 issuedJan. 27, 1970.

The lower portion of granulizer 12 and the subsequent granulizing rollsare not shown for clarity, and the path of material flow is indicated at26 for delivery to the input end of conveyor 14.

Conveyor 14 receives the granulized coffee from the granulizer mill andaxially moves it to the lower end of mixer 16 by suitable means such asthe auger or screw 28 mounted within housing 30 and powered by asuitable motor, not shown. A cooling jacket 32 may be provided aroundthe conveyor housing for circulation of a cooling medium such as waterto cool the granulized material.

Conveyor l4 discharges into mixer 16 preferably by side delivery to anopening 34 provided at the lower end of mixer chamber or shell 36. Theexact location for the point of delivery to the mixer chamber could beelsewhere, such as at chamber bottom wall 38, but should be positionedto feed the mixer from its lower portion for upward movement. lt hasbeen found that this provides a gravity head on the material in themixing chamber for optimum mixing characteristics, as explainedhereinafter.

Mixer chamber 36 preferably has a cylindrical configuration forrotatably mounting rotor assembly 40. Rotor assembly 40 comprises aplurality of radially extending members, here paddles or blades 42mounted by suitable means, such as by keyed hub 43, on shaft 44 forrotation about a substantially verticalaxis within the chamber. Therotor assembly may be driven in coordination with conveyor 14 bysuitable means such as an electric motor and drive arrangement, notshown, connected with shaft extension 45 depending downwardly through abearing support 47 in bottom wall 38.

The mixer blades 42 are arranged axially along shaft 44 in a series offlights with four blades in each flight secured to the shaft hub andwith spacing, as viewed axially, between blades. Five spacedapartflights 46, 48, 50, 52, 54 are illustrated as preferred, although it isunderstood that the number of flights required for mixing and the numberof blades in each flight can be varied as required by the particulardesign configuration and flow capacity desired. As illustrated in H6. 2alternate flights are preferably aligned with their blades at staggeredangles when viewed axially to achieve uniform mixing, although thisblade positioning could be varied without departing from the invention.

A plurality of radially and inwardly extending stationary agitatingfingers or pins 56 are secured to the walls of chamber 36 at axialpositions between the blade flights. Fingers 56 are shown as rod shaped,although they could be flat, and they function to provide resistance torotation and increase the agitation as the blades rotate. Otherwise thematerial would tend to merely rotate with the blades withoutsatisfactory chaff comminution and color hiding qualities. Although fourfingers 56 are shown as positioned on either side of flight 46 atequally spaced locations about shaft 44, the exact number and locationthereof could be varied as required.

The blades 42 in each flight are axially inclined so that as shaft 44rotates the blades will both mix and elevate the coffee. In theembodiment illustrated the blades are inclined to function in thismanner for clockwise rotation of shaft 44, when viewed from above,although this would be reversed for counterclockwise rotation. Theinclination of the blades may be varied, as from l535, for example,depending upon the design configuration of a particular application. Theindividual blades may be flat, as shown, although they may be curved ortwisted to effect the mixing action.

A flight of flow restricting blades 58 is mounted on shaft 44 at aposition axially spaced above mixing flights 46-54. The blades 60, shownas four, of flight 58 have a reverse inclination to that of mixer blades42 so that the upward flow of material within chamber 36 is restrictedsomewhat. The angle of inclination may be within the range of 5-20. Thisrestriction provides an additional pressure head on the material beingmixed and yet allows the material to flow into discharge end 18 at apredetermined rate. Although one flight of restricter blades is shown aspreferred, a plurality of flights could be provided depending upon thedesired head of a particular mixer construction, The blades may be flat,as shown, curved or twisted as desired.

Applicants have found that control of the amount of head maintained onthe material in the mixer chamber as a function of input flow rate,rotor speed, and amount of outlet restriction gives a consequent controlover chaff comminution, oil release from the coffee, and quality of thecoffee product. Excessive head will create highly undesirable fines inthe end product since coffee will be comminuted along with the chaff. Aninsufficient head will cause inadequate comminution of chaff and anundesirable, light-colored chaff flake will be visible in the endproduct. Also, the mixing action will knock the comers off the largecoffee particles and compact the small particles into coherent massesfor improved bulk density.

The head in the the mixer may be additionally controlled by regulatingthe rate of material flow or spill from the output end of mixer chamber36, such as with an adjustable spill at the outlet, not shown, toregulate the height of the material maintained within the chamber.

Control of the head also results in less temperature rise in the productduring mixing. One embodiment of the invention showed that thetemperature rise was from 5-1Q F. lower as compared to conventionalequipment. The result is that there is less release of coffee oils whichwould otherwise detrimentally affect the finished product, both in tasteand in handling qualities. Also with the present equipment the coffeemust be held for a period of time before packaging to reduce thepossibility of exploding coffee cans due to heat-generated gases. Thepresent invention reduces this holding time considerably.

In operation, with the combined action of the screw conveyor addingcoffee at the bottom and the rotation of rot0r 40 an upward thrust onthe mass in the chamber is maintained with the top flight tending toresist upward movement. The coffee particles will spill over the top ofmixer baffle 62 for subsequent treatment, preferably into a scalperdevice or vibrating screen, not shown, which could be mounted at theupper or discharge end of mixer 16. An upper skimming arm 64 mounted forrotation with rotor shaft 44 may be employed to brush or distribute thecoffee laterally onto the scalper screen surrounding baffle 62 andspread out the oversize particles. An upstanding skirt or shield 66 issecured to the mixer baffle may be employed to deflect particles awayfrom an oversize discharge spout, not shown, in the scalper. The finesand normal particles which would go through the screen may be deliveredby suitable means to the point of use for further handling andpackaging.

What is claimed is:

1. For use with a coffeedreating apparatus having a granulizer forreducing coffee beans, and means to convey the granulized coffeematerial from the granulizer, the combination including: an upstandingmixer chamber in material receiving communication at its lower end withthe conveyor; a mixer rotor mounted for rotation about a substantiallyvertical axis within the chamber; a plurality of mixer blades mountedfor rotation with the rotor for agitating and blending the coffeereceived from the conveyor during upward movement thereof within thechamber; and, means at the upper end of chamber to restrict upward flowof the coffee for developing a pressure head within the chamber.

2. The invention of claim 1 wherein the mixer blades comprise aplurality of blade flights axially spaced along the rotor, each bladeflight having a plurality of blades adapted to mix the coffee and urgeit upwardly within the chamber.

3. The invention of claim 2 wherein a plurality of blades are inclinedaxially in a direction to urge the coffee upwardly upon rotation of therotor.

4. The invention of claim 1 and further including a plurality ofagitator fingers mounted on the mixer chamber and extending radiallyinto the path of material flow adjacent the mixer blades.

5. The invention of claim 1 wherein the means to restrict the coffeeflow comprises at least one flight of flow restrictor blades mounted forrotation with the rotor at the discharge end of the chamber.

6. The invention of claim 5 wherein a plurality of the restrictor bladeshave an axial inclination effective to limit discharge of the coffeeduring rotation of the rotor to supplement said pressure head.

7. The invention of claim 6 wherein the mixer blades have an axialinclination reversed from the axial inclination of the restrictorblades.

8. A coffee mixer for use in treating granulized coffee comprising thecombination of: an upstanding chamber; a plurality of mixer membersmounted for rotation about a substantially vertical axis within thechamber and adapted to receive granu' lized coffee at the lower end ofthe chamber for agitating and mixing the coffee during upward movementthereof to the upper discharge end of the chamber; said mixer membersbeing in contact with coffee within the mixing chamber over the entirearea of movement of said mixer arms, and, means at the chamber dischargeend to restrict flow therefrom and develop a pressure head on the coffeebeing mixed within the chamber.

9. A coffee mixer for use in treating granulized coffee comprising thecombination of: an upstanding chamber; a plurality of mixer bladesmounted for rotation about a substantially vertical axis within thechamber and adapted to receive granulized coffee at the lower end of thechamber for agitating and mixing the coffee during upward movementthereof to the upper discharge end of the chamber; and means at thechamber discharge end to restrict flow therefrom and develop a pressurehead on the coffee being mixed within the chamber, said means forrestricting the flow comprising a plurality of restrictor blades mountedfor rotation about a substantially vertical axis at the chamberdischarge end, the restrictor blades having an axial inclination tendingto urge the coffee downwardly during blade rotation.

10. The invention of claim 9 wherein the mixer blades comprise aplurality of blade flights axially spaced within the chamber, the bladeflights having a plurality of blades with an inclination effective totend to move the coffee upwardly within the chamber during mixer bladerotation, and a plurality of agitator fingers mounted on the chamber andextending radially into the chamber adjacent the mixer flights.

11. The invention of claim 10 and further including a rotor mounted forrotation about said axis, and characterized in that the mixer blades andrestrictor blades are mounted for rotation with the rotor, the mixer andrestrictor blades having oppositely inclined angles to develop said headwithin the chamber during rotation of the rotor.

12. The method of treating coffee including the steps of: granulizingcoffee beans; conveying the granulized coffee to the lower end of amixing chamber, moving the coffee upwardly within the chamber under apressure head; mixing the coffee within the chamber to comminute chaffand release oil from the coffee for absorption into the chaff;restricting the rate of coffee flow from the chamber discharge end; and,discharging the coffee from the chamber for subsequent treatment.

13. The method of claim 12 wherein the step of conveying the coffee tothe chamber includes moving the coffee with a screw conveyor to forcethe coffee into the chamber under pressure, and the step of mixing thecoffee comprises rotating a plurality of mixer blades about anupstanding axis within the chamber.

14. The method of claim 13 wherein the step of restricting the flow fromthe chamber comprises rotating a plurality of blades at the dischargeend about an upstanding axis with the blades having an axial inclinationeffective to tend to urge the material downwardly.

15. The method of mixing granulized coffee in a mixing chambercomprising the steps of: forcing granulized coffee from a coffeeconveyor means into the lower portion of a generally vertically axisedchamber; moving the coffee upwardly within the chamber under a pressurehead existing within the entire body of coffee whose periphery isdefined by the paths of movement of mixer members, while agitating thecoffee with said mixer members; and restricting discharge of the coffeefrom the chamber at a location above the mixer members.

16. The method of claim 15 wherein the step of mixing includes moving aplurality of mixer members about an upright axis within the chamber, themembers having an orientation effective to urge the coffee upwardly andagitate the coffee while comminuting the chaff.

17. The method of claim 16 wherein the mixer members are moved aboutsaid axis in a plurality of axially spaced flights, and the members aremoved between a plurality of agitator fingers on the chamber radiallyextending adjacent the flights.

18. The method of mixing granulized coffee in a mixing chambercomprising the steps of: forcing granulized coffee from a coffeeconveyor means into the lower portion of the chamber; moving the coffeeupwardly within the chamber under a pressure head while agitating thecoffee with mixer blades; and, restricting discharge of the coffee fromthe chamber at a location above the mixer blades by moving a pluralityof restrictor blades about an upright axis at a location within thechamber above the mixer blades, the restrictor blades having an axialinclination effective to urge the coffee downwardly during restrictorblade rotation.

19. The method of mixing granulized coffee in a mixing chambercomprising the steps of: forcing granulized coffee from a coffeeconveyor means into the lower portion of the chamber; moving the coffeeupwardly within the chamber under a pressure head while agitating thecoffee with mixer blades; and, restricting discharge of the coffee fromthe chamber at a location above the mixer blades, said steps of mixingand restricting the coffee discharge being effected by simultaneouslyrotating a plurality of mixer blades and restrictor blades about anupright rotor within the chamber, the restrictor blades being positionedon the rotor above the mixer blades, the mixer blades having an axialinclination effective to urge the coffee upwardly, and the restrictorblades effective to urge the coffee downwardly to establish a pressurehead within the chamber while discharging the coffee.

2. The invention of claim 1 wherein the mixer blades comprise aplurality of blade flights axially spaced along the rotor, each bladeflight having a plurality of blades adapted to mix the coffee and urgeit upwardly within the chamber.
 3. The invention of claim 2 wherein aplurality of blades are inclined axially in a direction to urge thecoffee upwardly upon rotation of the rotor.
 4. The invention of claim 1and further including a plurality of agitator fingers mounted on themixer chamber and extending radially into the path of material flowadjacent the mixer blades.
 5. The invention of claim 1 wherein the meansto restrict the coffee flow comprises at least one flight of flowrestrictor blades mounted for rotation with the rotor at the dischargeend of the chamber.
 6. The invention of claim 5 wherein a plurality ofthe restrictor blades have an axial inclination effective to limitdischarge of the coffee during rotation of the rotor to supplement saidpressure head.
 7. The invention of claim 6 wherein the mixer blades havean axial inclination reversed from the axial inclination of therestrictor blades.
 8. A coffee mixer for use in treating granulizedcoffee comprising the combination of: an upstanding chamber; a pluralityof mixer members mounted for rotation about a substantially verticalaxis within the chamber and adapted to receive granulized coffee at thelower end of the chamber for agitating and mixing the coffee duringupward movement thereof to the upper discharge end of the chamber; saidmixeR members being in contact with coffee within the mixing chamberover the entire area of movement of said mixer arms, and, means at thechamber discharge end to restrict flow therefrom and develop a pressurehead on the coffee being mixed within the chamber.
 9. A coffee mixer foruse in treating granulized coffee comprising the combination of: anupstanding chamber; a plurality of mixer blades mounted for rotationabout a substantially vertical axis within the chamber and adapted toreceive granulized coffee at the lower end of the chamber for agitatingand mixing the coffee during upward movement thereof to the upperdischarge end of the chamber; and means at the chamber discharge end torestrict flow therefrom and develop a pressure head on the coffee beingmixed within the chamber, said means for restricting the flow comprisinga plurality of restrictor blades mounted for rotation about asubstantially vertical axis at the chamber discharge end, the restrictorblades having an axial inclination tending to urge the coffee downwardlyduring blade rotation.
 10. The invention of claim 9 wherein the mixerblades comprise a plurality of blade flights axially spaced within thechamber, the blade flights having a plurality of blades with aninclination effective to tend to move the coffee upwardly within thechamber during mixer blade rotation, and a plurality of agitator fingersmounted on the chamber and extending radially into the chamber adjacentthe mixer flights.
 11. The invention of claim 10 and further including arotor mounted for rotation about said axis, and characterized in thatthe mixer blades and restrictor blades are mounted for rotation with therotor, the mixer and restrictor blades having oppositely inclined anglesto develop said head within the chamber during rotation of the rotor.12. The method of treating coffee including the steps of: granulizingcoffee beans; conveying the granulized coffee to the lower end of amixing chamber, moving the coffee upwardly within the chamber under apressure head; mixing the coffee within the chamber to comminute chaffand release oil from the coffee for absorption into the chaff;restricting the rate of coffee flow from the chamber discharge end; and,discharging the coffee from the chamber for subsequent treatment. 13.The method of claim 12 wherein the step of conveying the coffee to thechamber includes moving the coffee with a screw conveyor to force thecoffee into the chamber under pressure, and the step of mixing thecoffee comprises rotating a plurality of mixer blades about anupstanding axis within the chamber.
 14. The method of claim 13 whereinthe step of restricting the flow from the chamber comprises rotating aplurality of blades at the discharge end about an upstanding axis withthe blades having an axial inclination effective to tend to urge thematerial downwardly.
 15. The method of mixing granulized coffee in amixing chamber comprising the steps of: forcing granulized coffee from acoffee conveyor means into the lower portion of a generally verticallyaxised chamber; moving the coffee upwardly within the chamber under apressure head existing within the entire body of coffee whose peripheryis defined by the paths of movement of mixer members, while agitatingthe coffee with said mixer members; and restricting discharge of thecoffee from the chamber at a location above the mixer members.
 16. Themethod of claim 15 wherein the step of mixing includes moving aplurality of mixer members about an upright axis within the chamber, themembers having an orientation effective to urge the coffee upwardly andagitate the coffee while comminuting the chaff.
 17. The method of claim16 wherein the mixer members are moved about said axis in a plurality ofaxially spaced flights, and the members are moved between a plurality ofagitator fingers on the chamber radially extending adjacent the flights.18. The method of mixing granulized coffee in a mixing chambercomprising the steps of: forcing granulized coffee from a coffeeconveyor means into the lower portion of the chamber; moving the coffeeupwardly within the chamber under a pressure head while agitating thecoffee with mixer blades; and, restricting discharge of the coffee fromthe chamber at a location above the mixer blades by moving a pluralityof restrictor blades about an upright axis at a location within thechamber above the mixer blades, the restrictor blades having an axialinclination effective to urge the coffee downwardly during restrictorblade rotation.
 19. The method of mixing granulized coffee in a mixingchamber comprising the steps of: forcing granulized coffee from a coffeeconveyor means into the lower portion of the chamber; moving the coffeeupwardly within the chamber under a pressure head while agitating thecoffee with mixer blades; and, restricting discharge of the coffee fromthe chamber at a location above the mixer blades, said steps of mixingand restricting the coffee discharge being effected by simultaneouslyrotating a plurality of mixer blades and restrictor blades about anupright rotor within the chamber, the restrictor blades being positionedon the rotor above the mixer blades, the mixer blades having an axialinclination effective to urge the coffee upwardly, and the restrictorblades effective to urge the coffee downwardly to establish a pressurehead within the chamber while discharging the coffee.